CONSOLIDATED STATEMENTS OF CASH FLOWS (USD $)
In Thousands, unless otherwise specified
12 Months Ended
Dec. 31, 2014
Dec. 31, 2013
Dec. 31, 2012
Cash Flows from Operating Activities      
Net income $ 32,774 $ 28,726 $ 22,357
Adjustments to reconcile net income to net cash provided by operating activities:      
Stock-based and non-cash compensation 1,187 1,079 991
Depreciation and amortization 8,456 8,598 8,759
Premises and equipment impairment     1,421
Provision for loan losses 2,000 7,500 16,500
Fair value adjustment on employee stock ownership plan shares allocated     (322)
Provision for deferred income taxes 12,715 10,110 8,571
Amortization of security premiums and discounts, net 7,305 8,744 9,730
Net security gains (776) (553) (1,597)
Gain on sales of loans, net (4,723) (10,227) (12,535)
Increase in cash surrender value of bank owned life Insurance (796) (1,189) (1,603)
Net gains on disposition of premises and equipment (19) (533)  
Net gains on disposition of OREO properties (162) (260) (274)
Increase (decrease) in deferred compensation 363 (49) (70)
Change in assets and liabilities:      
Decrease in other assets 2,274 9,880 8,368
(Decrease) increase in other liabilities (650) (63) 992
Net cash provided by operating activities before activities for loans originated for sale 59,948 61,763 61,288
Loans originated for sale (222,976) (450,226) (576,862)
Proceeds from sales of loans 231,139 486,616 564,643
Net cash provided by operating activities 68,111 98,153 49,069
Cash Flows from Investing Activities      
Purchases of securities classified available for sale (182,123) (83,718) (454,538)
Purchases of securities classified held to maturity (1,026) (839)  
Proceeds from sales of securities classified available for sale 74,113 16,365 59,570
Proceeds from maturities of securities classified available for sale 185,329 203,908 217,797
Proceeds from maturities of securities classified held to maturity 10    
Net increase in loans (126,604) (258,366) (33,680)
Purchases of premises and equipment (3,778) (2,549) (8,611)
Proceeds from disposition of premises and equipment 78 2,856 77
Proceeds from sale of OREO properties 2,739 3,645 14,950
Net cash used in investing activities (51,262) (118,698) (204,435)
Cash Flows from Financing Activities      
Net decrease in certificates of deposit (86,300) (108,828) (116,287)
Net increase (decrease) in demand deposits, money market and savings accounts 118,010 (2,326) 333,125
Net increase in federal funds purchased and securities sold under agreements to repurchase 26,545 33,324 11,157
Principal payments on long-term debt   (7,000) (12,000)
Proceeds from long-term debt 50,000    
Value of shares surrendered upon vesting of restricted stock units to cover tax obligations (45) (237)  
Cash dividends paid (17,224) (14,040) (24,427)
Net cash provided by (used in) financing activities 90,986 (99,107) 191,568
Net increase (decrease) in cash and due from banks 107,835 (119,652) 36,202
Cash and due from banks, beginning 231,603 351,255 315,053
Cash and due from banks, ending 339,438 231,603 351,255
Cash Payments for:      
Interest 6,665 9,086 15,523
Income taxes 6,395 4,749 1,045
Non-cash Investing and Financing Activities:      
Other real estate acquired in settlement of loans 660 2,068 9,674
Employee stock ownership plan shares allocated     $ 417